Turtle Fast is now live

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Private beta · limited slots

Your AI,
on a phone call.

One agent. One number. Takes calls you miss, makes calls you dread, follows flows you design, and chats with you and your customers. A second you, on the line.

Works on
Any phone
signal only
Setup
60 seconds
no app
Data
Isolated
never trained on
No Internet
9:41

Turtle

mobile

0:47

You“What time does REI close today?”
mute
keypad
audio
Works anywhere
Set up your line

One step away from
a better way to be reached.

Stand up a personal customer line for the product or service you offer — so the people trying to reach you actually get through. Your agent answers, triages, books, follows up, and hands off the ones that matter. You stay focused; they get a response worth remembering.

My Agent

A version of you, on the line.

Name it. Pick a voice. Set the tone to Concise, Friendly, or Professional. Upload PDFs and notes so it answers like you would.

Persistent memory across calls
Upload .txt, .md, .pdf (up to 10 MB)
You control what it remembers, always
Identity
Turtle
Concise
Friendly
Professional
“The meeting is at 3 PM. Want me to add it to your calendar?”
Context docs3 / 10
calendar-rules.pdfready
team-names.mdready
prefs.txtprocessing
Make a Call

It dials the hard calls for you.

Book the reservation. Cancel the subscription. Call the clinic. Give it context, it dials out and reports back.

Connected
To
+1 415 555 0188
01:24
Call History

Every call, summarized.

Private to you, searchable in seconds.

Bella Vita reservation confirmed
outbound · 1m 12s · 2h ago
Hike check-in, added dentist Fri 10 AM
inbound · 38s · yesterday
Flagged urgent email from Alex, called you
gmail · 2 days ago
Call Flows

Design the exact conversation
your agent will have.

Call Flows is a visual builder for branching, scripted conversations. Drop in greetings, questions, logic, handoffs, and endings. Run as many flows as you want, your agent uses the one marked active.

Start from a template
Smart screener, lead qualifier, service dispatcher, restaurant reservations, or build from scratch.
Dry-run before you go live
Step through a simulated call in the dashboard. See exactly what your agent says at each branch.
Describe it in English
Type "screen calls, patch family through, text me a summary of the rest" and we'll scaffold the flow for you.
Try the flow builder
ActiveSmart screener
who + whyinvestorprospectcold reach
Trigger · Inbound
Someone calls your founder line
Speak
“Hi, this is Turtle for Alex — what’s this about?”
Classify caller
running
Match against your contacts · score intent
Investor
Known VC domain or warm intro.
Customer
Inbound lead, asking about pricing.
Cold outreach
Recruiter, agency, or vendor pitch.
Patch through
Ring your cell. SMS you the context first.
Book a demo
Qualify, drop a Cal link, post to #sales.
Decline & log
Send a no-thanks template. Log and move on.
drag to add
9 nodes · 8 edges
LiveSMS · Web chat
Today · 2:14 PM
MR
hey, evaluating tools like yours for our 20-person eng team. any chance of a quick call with Alex this week?
+1 (415) 555-0184 · 2:14 PM
Hi! This is Turtle for Alex. He's heads-down on a release this week, but Thursday 2 PM or Friday 11 AM PT work. Which do you prefer?
Turtle · 2:14 PM
MR
thursday 2pm works. do you support SSO/SAML?
calendar.book()→ 200
Locked in Thursday 2 PM PT. Yes, SSO/SAML is on the Team plan — Alex will walk you through setup. Calendar invite and one-pager on the way.
MR
perfect, thanks
Jump in and take over…⏎
Also over chat

Same agent. Every channel.

Not every customer wants to call. Your agent replies to texts and web chat with the same voice, same flows, same memory — and hands off to you the second things get real.

SMS, web widget, WhatsApp
One agent answers on all of them. Replies feel native, no "press 1 for" energy.
Remembers across channels
The customer who called yesterday and texts today talks to an agent that knows them.
Jump in any time
Type into the same thread and the agent steps back. Reply "turtle take over" to hand it back.
Try it in a text
Integrations

Give your agent hands.

Plug your agent into the tools you already live in. It reads, writes, and reasons across them, then calls you when something matters.

Gmail
Reads inbound mail. Calls you about urgent messages. Drafts replies on command.
OAuth · read + send scopes
Google Calendar
"Add dentist Friday at 10." Done. Your agent reads your schedule before answering.
In private testing
Slack
DMs from your boss get a call. Channel noise doesn't. You define what counts.
On the roadmap
Microsoft 365
Outlook and Teams parity for folks on the Microsoft stack.
On the roadmap
Notion
Sync docs and wikis into context. Your agent answers from your team's knowledge.
On the roadmap
Webhooks & API
Wire your agent into any system. Call start, call end, and summary webhooks.
Ask us →

Live in 60 seconds.

01

Claim your number

Sign up and we'll provision a real US phone number for your agent. Save it in your contacts as "Turtle".

02

Set up in the dashboard

Pick a voice and personality. Upload any context. Connect Gmail. Pick an active call flow.

03

Call from anywhere

Dial and talk, or send your agent to talk on your behalf. Every call summarized back in the dashboard.

Privacy

Your voice. Your data.

We built Turtle privacy-first. Your data never trains anyone else's model. Your agent runs in its own isolated container, not shared with any other user.

Your own personal wiki
Every call, transcript, and note your agent learns lands in a private knowledge base you own. Search it, edit it, delete any entry with one click.
Isolated containers
Every user gets a dedicated runtime. No shared memory, no cross contamination.
Never trained on your data
Your conversations don't improve anyone else's model. Clear your memory anytime.
NewTurtle Fast · Speech-to-Speech API

Voice AI that doesn’t wait its turn.

Turtle Fast is our real-time, full-duplex speech-to-speech API. Open one WebSocket, stream audio in, and hear audio back in under 250ms — with native barge-in, phone-grade audio, and an event shape that’s drop-in compatible with the OpenAI Realtime API.

api.turtlefast.com
TTFB 230ms
Youspeaking
Agentresponding
Both streams stay open at once — the caller can interrupt mid-sentence and the model adjusts.
event streamOpenAI Realtime shape
→session.update
←input_audio_buffer.speech_started
←response.output_audio.delta× streaming
←response.function_call_arguments.done
←response.done
One pass, not three
STT→LLM→TTS
Cascade · 3 models · tone discarded · seconds of lag
Speech-to-speech
One model · tone preserved · first audio in <250ms
≤250ms
to first audio byte
Full-duplex
native barge-in
OpenAI
Realtime-API compatible
G.711
μ-law / A-law, no transcode
Full-duplex, with barge-in
It listens and speaks at once. Talk over it and it stops, listens, and adjusts — just like a real conversation.
Hears tone, not just words
It works on audio directly instead of flattening you to text first. Frustration, hesitation, sarcasm — it all stays in the loop.
One pass, not three
A single speech-to-speech model replaces ASR → LLM → TTS, so the first sound comes back in a fraction of a second.
Drop-in OpenAI Realtime shape
Mirrors the OpenAI Realtime API event shape. If you've already built against it, point your client at our wss:// and go.
Native phone audio
Accepts G.711 μ-law/A-law straight from Twilio Media Streams — no transcoding, no added latency on your side.
Tools & function calling
Call your functions, MCP servers, and hosted web/file search mid-conversation — then keep talking, naturally.
quickstart.js
const ws = new WebSocket(
"wss://api.turtlefast.com/v1/realtime?model=v1"
);
 
ws.send(JSON.stringify({
type: "session.update",
session: {
voice: "turtle",
input_audio_format: "g711_ulaw", // from Twilio
turn_detection: { type: "server_vad" },
tools: [{ type: "function", name: "lookup_order" }]
}
}));

Build your own voice agent.

Sign up to create an API key and access the speech-to-speech API — the same engine behind Turtle, now in your stack.

Sign up to get an API key
wss://api.turtlefast.com/v1/realtime

Questions?

Turtle is cloud-hosted. When someone calls your Turtle number, the call routes over the phone network — your phone only needs cell signal, whether you're dialing Turtle yourself or getting a patched-through call from your agent.

Any phone that can make calls: iPhone, Android, flip phone, or a landline. If you can dial a number, you can use Turtle.

A visual builder for scripted conversations. You can have dozens of flows, a smart screener for your personal number, a lead qualifier for your business line, a dispatcher for after-hours, and switch which one is active at any time.

Yes. Use Make a Call in the dashboard (or ask your agent on the line) to dial out, restaurants, customer service, clinics. It handles the conversation and reports back.

Connect Gmail in a click via OAuth. Your agent reads inbound mail and calls you about urgent messages. Google Calendar, Slack, and Microsoft 365 are on the way.

Yes. From My Agent you pick a voice, name it, and set personality to Concise, Friendly, or Professional. Upload .txt/.md/.pdf docs to give it context.

Turtle Fast is our real-time, full-duplex speech-to-speech voice API for developers — the same engine behind Turtle, now available to build on. Open a WebSocket, stream audio in, and get audio back in under 250ms, with native barge-in and phone-grade audio. It mirrors the OpenAI Realtime API event shape, so it's close to a drop-in. Sign up to create an API key and start building.

No credit card · cancel anytime

Stop tapping.
Just call.

Claim a real phone number for your AI agent. Set it up in 60 seconds. Start calling from anywhere.